Acknowledgements

This module was created by Tina Grotzer and Margot Sudbury with contributions from a number of individuals. Dorothy MacGillivray, Rebecca Lincoln, and Sarah Mittlefehldt made numerous substantive improvements and worked diligently to bring the module to fruition. Eric Buchovecky offered detailed and insightful comments on the teaching and learning challenges involved. David Perkins provided insights on the nature of the causalities involved. Belinda Bell Basca, Kiki Donis, Dorothy MacGillivray, and Melanie Pincus assisted in analyzing the data that we collected on teaching the concepts in these lessons. Dorothy MacGillivray was responsible for much of the design and lay-out. Rebecca Lincoln made numerous edits to strike a balance between clarity and accuracy given the complexity of the material. Sarah Mittlefehldt worked magic editing images and diagrams. Kiki Donis and Rebekah Gould helped to develop diagrams and explanations. We are especially appreciative to our science consultants: Roger Sudbury, Electrical Engineer at MIT and Joseph Snir, Physics Education Professor at the University of Haifa, Israel, for their patience with our many questions and their good humor in finding ways to explain complex concepts in ways that students could grasp. We are immensely grateful to Nora Sabelli, Ken Whang, and Elizabeth Vanderputten at the National Science Foundation for their support and guidance. The teachers in the Burlington, Arlington, and Billerica, MA Public Schools, specifically David Thibault, Kim Piccolo, Jim Stanger, Lynda Verity, Gini MacAuley, Eric Buchovecky, and Eileen Kenneally worked with us to test the concepts with their students. We are grateful to them for their patience and insight. Thank you to John Papadonis of the Burlington Schools' Science Center for his support and helpful suggestions. We thank the administrators, Dr. Bill Conners, Mr. Richard Connors, Dr. Joanne Gurry, Mr. Stephen Carme, Mr. Mike McCabe, Dr. Thomas Sharkey, and Mr. Joseph LoDuca. We especially thank the many students who shared their thinking with us over the past six years.

This work was supported by the National Science Foundation, Grant No. REC-9725502 and No. REC-0106988 to Tina Grotzer and David Perkins, Co- Principal Investigators. Any opinions, findings, conclusions or recommendations expressed here are those of the authors and do not necessarily reflect the views of the National Science Foundation.